diff --git a/classes/CommandInterpreter.php b/classes/CommandInterpreter.php
new file mode 100644
index 0000000000..58e6a9c07c
--- /dev/null
+++ b/classes/CommandInterpreter.php
@@ -0,0 +1,336 @@
+<?php
+/*
+ * Laconica - a distributed open-source microblogging tool
+ * Copyright (C) 2008, Controlez-Vous, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('LACONICA')) { exit(1); }
+
+class CommandInterpreter {
+	
+	function handle_command($user, $text) {
+		# XXX: localise
+
+		$text = preg_replace('/\s+/', ' ', trim($text));
+		list($cmd, $arg) = explode(' ', $text, 2);
+
+		# We try to support all the same commands as Twitter, see
+		# http://getsatisfaction.com/twitter/topics/what_are_the_twitter_commands
+		# There are a few compatibility commands from earlier versions of 
+		# Laconica
+		
+		switch(strtolower($cmd)) {
+		 case 'help':
+			if ($arg) {
+				return NULL;
+			}
+			return new HelpCommand($user);
+		 case 'on':
+			if ($arg) {
+				list($other, $extra) = explode(' ', $arg, 2);
+				if ($extra) {
+					return NULL;
+				} else {
+					return new OnCommand($user, $other);
+				}
+			} else {
+				return new OnCommand($user);
+			}
+		 case 'off':
+			if ($arg) {
+				list($other, $extra) = explode(' ', $arg, 2);
+				if ($extra) {
+					return NULL;
+				} else {
+					return new OffCommand($user, $other);
+				}
+			} else {
+				return new OffCommand($user);
+			}
+		 case 'stop':
+		 case 'quit':
+			if ($arg) {
+				return NULL;
+			} else {
+				return new OffCommand($user);
+			}
+		 case 'follow':
+		 case 'sub':
+			if (!$arg) {
+				return NULL;
+			}
+			list($other, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else {
+				return new SubCommand($user, $other);
+			}
+		 case 'leave':
+		 case 'unsub':
+			if (!$arg) {
+				return NULL;
+			}
+			list($other, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else {
+				return new UnsubCommand($user, $other);
+			}
+		 case 'get':
+		 case 'last':
+			if (!$arg) {
+				return NULL;
+			}
+			list($other, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else {
+				return new GetCommand($user, $other);
+			}
+		 case 'd':
+			if (!$arg) {
+				return NULL;
+			}
+			list($other, $extra) = explode(' ', $arg, 2);
+			if (!$extra) {
+				return NULL;
+			} else {
+				return new MessageCommand($user, $other, $extra);
+			}
+		 case 'whois':
+			if (!$arg) {
+				return NULL;
+			}
+			list($other, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else {
+				return new WhoisCommand($user, $other);
+			}
+		 case 'fav':
+			if (!$arg) {
+				return NULL;
+			}
+			list($other, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else {
+				return new FavCommand($user, $other);
+			}
+		 case 'nudge':
+			if (!$arg) {
+				return NULL;
+			}
+			list($other, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else {
+				return new NudgeCommand($user, $other);
+			}
+		 case 'stats':
+			if ($arg) {
+				return NULL;
+			}
+			return new StatsCommand($user);
+		 case 'invite':
+			if (!$arg) {
+				return NULL;
+			}
+			list($other, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else {
+				return new InviteCommand($user, $other);
+			}
+		 case 'track':
+			if (!$arg) {
+				return NULL;
+			}
+			list($word, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else if ($word == 'off') {
+				return new TrackOffCommand($user);
+			} else {
+				return new TrackCommand($user, $word);
+			}
+		 case 'untrack':
+			if (!$arg) {
+				return NULL;
+			}
+			list($word, $extra) = explode(' ', $arg, 2);
+			if ($extra) {
+				return NULL;
+			} else if ($word == 'all') {
+				return new TrackOffCommand($user);
+			} else {
+				return new UntrackCommand($user, $word);
+			}
+		 case 'tracks':
+		 case 'tracking':
+			if ($arg) {
+				return NULL;
+			}
+			return new TrackingCommand($user);
+		 default:
+			return false;
+		}
+	}
+}
+
+class Channel {
+	
+	function on($user) {
+	}
+
+	function off($user) {
+	}
+
+	function output($user) {
+	}
+	
+	function error($user) {
+	}
+}
+
+class Command {
+	
+	var $user = NULL;
+	
+	function __construct($user=NULL) {
+		$this->user = $user;
+	}
+	
+	function execute($channel) {
+		return false;
+	}
+}
+
+class UnimplementedCommand extends Command {
+	function execute($channel) {
+		$channel->error(_("Sorry, this command is not yet implemented."));
+	}
+}
+
+class TrackingCommand extends UnimplementedCommand {
+}
+
+class TrackOffCommand extends UnimplementedCommand {
+}
+
+class TrackCommand extends UnimplementedCommand {
+	var $word = NULL;
+	function __construct($user, $word) {
+		parent::__construct($user);
+		$this->word = $word;
+	}
+}
+
+class UntrackCommand extends UnimplementedCommand {
+	var $word = NULL;
+	function __construct($user, $word) {
+		parent::__construct($user);
+		$this->word = $word;
+	}
+}
+
+class NudgeCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class InviteCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class StatsCommand extends UnimplementedCommand {
+}
+
+class FaveCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class WhoisCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class MessageCommand extends UnimplementedCommand {
+	var $other = NULL;
+	var $text = NULL;
+	function __construct($user, $other, $text) {
+		parent::__construct($user);
+		$this->other = $other;
+		$this->text = $other;		
+	}
+}
+
+class GetCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class SubCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class UnsubCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class OffCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other=NULL) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class OnCommand extends UnimplementedCommand {
+	var $other = NULL;
+	function __construct($user, $other=NULL) {
+		parent::__construct($user);
+		$this->other = $other;
+	}
+}
+
+class HelpCommand extends UnimplementedCommand {
+}